Activity 2.12 Class 10 Science

Soil P^H is the key factor that determines soil fertility, which helps farmers treat the soil to achieve good crop yields. 

This activity explains to us how to test the P^H of a soil sample using a universal indicator. You can also go through activity 2.11 of this chapter.

 

How does P^H affect Soil?

 

Aim of the activity

To test the P^H of the soil sample and analyze its suitability for plant growth in a particular region.

 

Materials used in the activity

   1.  Test tubes

   2.  Soil sample

   3. Distilled water  

   4. Funnel and filter paper

   5. Universal indicator and P^H paper

   6. Glass rod

Procedure

We put about 2 g of soil in a test tube and add 5 ml of distilled water to it and shake the contents of the test tube.

After mixing the contents, we filter the contents and collect the filtrate in a test tube.

Now we check the P^H of this filtrate with the help of universal indicator paper and match it with the standard P^H scale.

Observation

Colour on PH paper	PH value	Nature of soil
Red/orange	3-5	Strongly acidic
Yellow-green	6	Slightly acidic
Green	7	Neutral
Blue	8	Slightly basic
Violet	9 -11	Strongly basic

 

Explanation

The different P^H of the soil is due to salts and minerals present in the soil.

Conclusion 

This activity helps us understand the chemical nature of the soil.

The best P^H value range for soil is approximately 6 to 7, as this is the range in which most nutrients can be readily available.

Frequently Asked Questions

   1. What is the ideal soil P^H for crops?

Answer – The P^H between 6 to 7.5 is good for most of the crops.

   2. How can acidic soil be corrected?

Answer – Alkaline substances like lime can be added to the soil.

   3.  Why is distilled water used in the activity?

Answer – Because distilled water has a P^H  7 (neutral), it cannot affect the P^H of the soil sample.

   4. Can different regions have different soil P^H levels?

Answer – Yes, soil P^H levels are different in different regions.